| June 30, | ||||||||
| 2013 | 2012 | |||||||
| Costs incurred on contracts in progress | $ | 3,463,691 | $ | 3,074,540 | ||||
| Estimated contract profit | 559,052 | 643,526 | ||||||
| 4,022,743 | 3,718,066 | |||||||
| Less: billings to date | 3,323,400 | 2,790,988 | ||||||
| Contract costs and related estimated profits in excess | ||||||||
| of billings | $ | 699,343 | $ | 927,078 | ||||